Pneumatically driven surgical instrument and control therefor



R. M. HALL Jan. 21, 1969 PNEUMATICALLY DRIVEN SURGICAL INSTRUMENT ANDCONTROL THEREFOR Filed April 5, 1967 R a m & Q Q

3 Q N I 3 a w v R R. R. W, x a, N v 8 Q a a X 8 w m N w RN L w um mm 3 hIQ 5 mm 8. m. N\ N Q $3 wm 0/. r M m w 5 W C r ,...A e am u m a e 0 N\M\ R mm mm Q 3 N\ NN United States Patent 3,423,068 PNEUMATICALLYDRIVEN SURGICAL INSTRU- MEN T AND CONTROL THEREFOR Robert M. Hall, 527Jenkins Bldg, Pittsburgh, Pa. 15222 Filed Apr. 5, 1967, Ser. No. 628,629US. Cl. 253-2 Int. Cl. F0141 15/06; F03b 13/00 8 Claims ABSTRACT OF THEDISCLOSURE A pneumatically driven surgical instrument having controlvalve actuator means longitudinally of the housing of the instrumentwhich precise variable finger tip control slidably guidable along thehousing body, the forward end of the housing and actuator means adaptedto be received with a pen-like grip. The rotary output spindle of theinstrument is angularly disposed relative to the housing for clarity ofvision.

BACKGROUND OF THE INVENTION Field of the invention The art of pneumaticdriven surgical instruments in the surgical armamentarium field isrelatively new. Such surgical appliances began to appear in the early1950s, such as Patent No. 2,740,406. Two more recent instruments arethose disclosed in Patents Nos. 3,128,079 and 3,223,088. Of these,Patents Nos. 2,740,406 and 3,223,088 make provision only for pneumaticcontrol of the pressurized gas to the surgical instrument through theuse of a slide valve at the rear of the instrument. Not only do thesetypes of control fail to give a precise variable but uniform control andrequire additional manipulative steps but also are inconvenientlylocated at the rear of the instrument, resulting in necessity ofemploying of two hands to properly operate and control the instrument.

Many times during surgical procedures, a surgeons hands must eachperform a different task. This is especially true in surgery requiringgreat dexterity and precision of skills such as in neurosurgical andendaural procedures and procedures under the operation microscope, nowcommonly referred to as microsurgery. The application of these types ofcontrols of the prior art would necessitate the use of both hands of thesurgeon and at the same time would bring about muscle fatigue quicklywhich would clearly affect the manual dexterity of the surgeon which, inturn, has a resultant adverse eifect on the surgeons surgical skills.

In the case of Patent No. 3,128,079, a pivotal lever type of control isprovided which requires the constant controlling attention of thesurgeons grasping of the handpiece. Muscle fatigue sets in soon in inthe"surgeons hand and it becomes increasingly diiiic'ult for the surgeonto maintain a constant controlled pressure on the lever without tensionshaking of the surgeons hand, adversely affecting the surgeons surgicalskills. Moreover, such a pivotal type of lever control requires theapplication of lateral manually applied force relative to thelongitudinal axis of the handpiece which, upon variance, during the useof such an instrument in a surgical procedure, will result in theapplication of a jerky or jarring movement on the handpiece. Thismovement, of course, will be directly transferred to the operative areawhere it may interfere with not only the talented surgical skills of thesurgeon but also cause undesired cutting procedures in the operativearea.

The present invention is to provide an instrument that provides the bestclarity of surgical procedure being per-formed and permits precisefeather-tip variable control of operating speeds without disadvantagesenumerated above.

SUMMARY OF INVENTION The present invention relates to a pneumaticallydriven surgical instrument for application in precision surgery whereclarity of vision is imperative and precise variable finger tip speedcontrol is necessary over a large range of speeds, acquired by theapplication of an angularly disposed output housing and spindle and acontrol valve actuator means slidably guided along the housing of theinstrument to extend the manual dexterity of the surgeon withoutcompromising any of his skills.

The offset angle of the output spindle, which may be thirty degrees ormore, allows clear vision and excellent maneuverability in microsurgery.

The precise variable finger tip control needs only a feather light touchto allow the application of delicate and highly diflicult bonetechniques. The variable speed finger tip control allows a range ofspeeds, from 20 r.p.m. to 20,000 rpm, depending on the needs of surgicalapplication, such as adequate torque, the best of which is obtainable atthe highest speeds permitting rapid gross bone cutting and removal.

The precise variable control lever actuating the pneumatic inlet valveassembly being slidable longitudinally of the housing of the handpieceor instrument eliminates the cause of any lateral motion to be createdto be carried by the handpiece output spindle to the end of the burr ortool inserted into the collet of the spindle having un wanted andundesirable effects in the area of surgical application.

The surgical instrument comprising this invention is designed to reduceand maintain, at a low level, the causes of muscle fatigue of theskillful surgeons hands with the purpose to extend the application ofthe surgeons skills and dexterical ability with the least possiblesacrifice.

The instrument is completely autoclavible and the expended gas from thepneumatic rotor is exhausted and diffused at the rearward end of theinstrument at a safe distance from the surgical field.

Other objects and advantages of this invention appear hereinafter in thefollowing description and claims.

The accompanying drawings show, for the purpose of exemplificationwithout limiting the present invention and claims thereto, certainpractical embodiments illustrating the nature and principles of thisinvention and application thereof wherein:

FIG. 1 is a longitudinal sectional view of the pneumatically drivensurgical instrument comprising this invention.

FIG. 2 is a cross-sectional view along the line 2-2 of FIG. 1.

FIG. 3 is a longitudinal sectional view of a modified form of couplinglinkage of the output spindle of the surgical instrument comprising thisinvention.

Referring to FIG. 1, there is shown a side elevation in cross section ofa pneumatically driven surgical instrument 1 for use in su gery andparticularly surgery involv- 3i ing .an operation requiring the use of amicroscope as in the case of many neurosurgical procedures, comprisinghousing or shell 2. The valve body 3 is provided on the rear end of theshell 2 and is secured thereto as shown at 4 which may have a threadedengagement or any other convenient form of engagement.

A spindle housing 5 is supported on the forward end of the shell 2 andin turn supports the angle housing 6 as shown at 7 through the use ofthe lock ring 9. The angle housing 6 comprises the forward end 8 of thehandpiece 10 and this portion of the handpiece is contoured to be firmlygrasped by the fingers. For example, the sides of the forward end 8 maybe recessed for grasping by the thumb and middle finger. The knoll 11 ofthe forward end may be recessed as shown at 12 to receive the end of theindex finger.

The angle housing 6 forward nose position designated as the fronthousing 13 to rotatably support the output spindle 14 within the alignedbearings 15. The bearings 15 are supported in the cylindrical recess 16on the inner surface of the front housing 13 and are secured in theiraligned position by the sleeve 17 and the bearing retainer 18 and theshoulder 24 of the nose cap 25.

The output spindle 14 may be in the form of a friction collet and/orhave a collet insert 20 in the slot 21. The collet spring 22 retains theinsert 20 normally within the slot 21 so that the collet insert 20 mayfrictionally engage the tool or burr within the spindle collet 23.

The nose cap 25 may be threadably secured at 26 to the front housing 13.

The rear portion of the output spindle 14 is secured by the shaft 27 tothe knee gear 28, the latter being in angular gear engagement with theknee gear 30.

The shell 2 houses the pneumatic rotor 31 which comprises the rotorshaft 32 supported by the aligned bearings 33 which, in turn, areconcentrically supported in the shell 2 on the bearing rings 34. Therotor blades 35 are held to rotate the shaft 32 by being keyed to theshaft 32 as shown at 39, the rotor inserts 36 providing a hermetic sealbetween the rotor housing encasement and the shaft 32 and bearings 33.

The rotor housing comprises the housing cylinder 37 which is maintainedin aligned and secure position by the alignment pins 38, which arerecessed in the bearing rings 34. The end walls of the rotor housingencasement comprises the front and rear end plates 40 and 41,respectively, the rear plate 41 being backed up by the vent plate 42both aligned by the pins 38. The cover plate 43 abuts the rear end ofthe rotor housing and receives forward end of the valve body 3 and isprovided with aligned holes to receive the alignment pins 38.

It should be noted that the alignment pins 38 extend also into therecesses 44 of the valve body 3. Thus, the above mentioned componentsmaking up the rotor housing encasement together with the bearings rings34 and the valve body 3 are maintained in aligned and secured position.

The forward end of the rotor shaft 32 is provided with the couplingdriver 45, the latter of which is connected to the spindle 46 in theforward end 8 of the angle housing 6. The spindle 46 is rotatablysupported at one end in the angle housing 6 by the bearing 47 and isrotatably supported at its other end by the bearing 48 which is securedin the spindle housing 5 against the shoulder 50 by the retaining ring51.

The spindle 46 has at its forward end the extension shaft 52 to which issecured the knee gear 30 for interengagement with the knee gear 28.

It can readily be seen that upon application of pneumatic pressure tothe rotor blades 35, the rotor shaft 32 will drive the spindle 46 which,in turn, drives the output spindle 14 through the knee gear assembly 28and 30.

The valve body 3 is provided with the swivel connector 53 secured to thevalve body 3 by the nut 54. The swivel connector 53 is connected to aflexible tubing (not shown) which supplies pneumatic pressure to thechamber 55 in the valve body 3. The oil fitting or plug 56 is providedin the inlet chamber 55 in order that oil may be introduced into thepneumatic supply to provide continual lubrication of the rotor 31.

The gas supply proceeds from the inlet chamber 55 to the valve means 57which comprises the ball valve 58 supported in the valve chamber 60 onthe lower and upper O-rings 61 and 62, respectively. The ball valve 58is provided with the valve stem 63 which has a rounded end portion 64 tobe received in the recess 65 of the valve actuator 66.

The ball valve 58 is provided with the cup-shaped recess 67 which, uponrotation of the ball valve 58, permits a selected amount of pressurizedgas to pass from the inlet chamber 55 through the base of the valvechamber 60, out the valve chamber outlet 68 to the passageway 70. Thecup-shaped recess 67 is unique in that its particular contour or shapepermits a controlled amount of pressurized gas to be supplied to therotor 31 permitting the pneumatically driven surgical instrument to havea wide variable range of speeds beginning at 20 r.p.m. up to 20,000 rpm.upon the mererotation of the ball valve 58 of an arcuate length ofapproximately forty-five degrees or less. Thus, the ball valve 58together with its cup-shaped recess 67 and the O-rings 61 and 62cooperate to provide a means for throttling the pressurized gas to therotor 31 in a precision manner to permit a selected desired amount ofpressurized gas to flow out of the valve chamber 60 into the passageway70.

From the passageway 70 the pressurized gas is directed through atransverse opening through the cover plate 43, the bearing ring 34,through the vent plate 42 and end plate 41. The pressurized gas thusenters the encasement of the rotor 31 where it is applied against therotor blades 35 to rotatably drive the shaft 32 and spindle 46.

Atop the housing encasement there is provided radial openings throughanother area of the end plate 41 and vent plate 42 for exhausting theexpended gases from the pneumatically driven rotor 31 through thepassageways 71 and 72 as shown in FIG. 2. The expended gas passageways71 and 72 traverse the entire length of the valve body 3 and areexhausted out of the valve body 3 at the exhaust outlet 73 through themuffler ring or diffuser 74. The muffler ring 74 is retained in itsproper position on the end of the valve body 3 by the muffier ring 75.

In providing more than one expended gas passageway in the valve body 3,the expended gas from the pneumatically driven rotor 31 is permitted toexit from the surgical instrument 1 as efliciently as possible and thusprevent any possibility of gas build-up in the rotor housing encasement.This reduces the possibility of gas leakage through other internalcomponents of the surgical instrument 1 or otherwise reducing theefficient operation of the rotor 31.

As noted in FIG. 2, the ball valve 58 is supported on the pivot screws76 which are secured within the valve body 3 and are provided with thepivoting points 77 to rotatably support the ball valve 58 within theO-rings 61 and 62.

As mentioned previously, the valve stem 63 of the ball valve 58 has therounded portion 64 which fits into the recess 65 of the valve actuator66. The recess 78 is provided in the valve body 3 for the valve actuator66. The retainer plate 80 is secured to the bottom of the recess 78 bythe screw member 81 in order to retain the ball valve 58 together withits O-rings 61 and 62 within the valve chamber 60. The retainer plate 80is provided with the opening 82 which is frusto-conical in cross sectionto permit the passage of the valve stem 63 for rotatable en casement inthe recess 65 of the valve actuator 66.

The rearward portion of the valve actuator 66 is provided with anannular opening 83 for retaining the coil spring 84 in the recess 78,which spring is biased against the back wall 85 of the recess 78. Thus,the valve actuator 66 is maintained in a normally forward position inthe recess 78 as shown in FIG. 1 until the valve actuator 66 is forcedrearwardly in the recess 78 to rotatably operate the valve means 57.

A unique principal feature of the surgical instrument 1 comprising thisinvention resides in the type of valve control wherein there is providedthe lever control 86 which is attached to the valve actuator 66 at itsrearward end by the screw member 87 and is slidably engagea-ble on thevalve body 3 in view of the collar 88. The forward end of the levercontrol 86 is provided with a buttress 90 which has an inwardly disposedguide groove 91 for guided slidable engagement on the lever pin guide92, the latter of which is secured to the forward end 8 of the surgicalinstrument 1. The buttress 90 is provided with the recessed area 93 toreceive the pad of the first phalanx of the index finger to forciblyoperate the lever control 86 and valve actuator 66 against the coilspring 84 to rotate the ball valve 58 within the valve chamber 60. Theamount of pressure applied on the buttress 90 may be varied in a precisemanner to bring about the rotational speed of the output spindle 14desired. Thus, only the light feather touch of the index finger isneeded to operate the surgical instrument 1 thereby enhancing thesurgeons dexterity in permitting him to extend without any compromisewhatsoever his skills to the immediate surgical procedure needs.

For extended application of the surgical instrument 1 the lever control'86 together with the valve actuator 66 may be provided with the lockingmeans 94 in the form of a lock screw threadably secured within the valveactuator 66 as indicated at 95 to project against the retainer plate 80and, thus, maintain the lever control 86 in the desired position. Itshould be noted the importance of the collar 88 in that it not onlyprovides for smooth operation of the lever control 86 but also retainsthe valve actuator 66 within the recess 78 of the valve body 3.

The controlling of a pneumatically driven surgical instrument for use insurgical procedures involving precision work, such as neurosurgicalprocedures or operations performed under an operation microscope,requires a unique valve actuating means and control lever as against thepreviously known type of valve actuating controls found in the priorart. A slidable guided control lever permits precise movement of thecontrol lever and therefore precise control of the valve meansespecially like the control lever 86 of the present application whichpermits a grasping of the surgical instrument 1 in the palm of ones handwhich results in complete freedom of use of the index finger and thusthe best possible manual dexterity of the same in applying a variablebut selective force on the buttress 90 of the lever control 86. In thisconnection, it is also very important to note that control leversutilized in the prior art, such as an outwardly pivoting control leveras in Patent No. 3,128,079, permit the application of a hand squeezingmaneuver in controlling the surgical instrument which is undesirable inprecision surgery of the type heretofore mentioned since the results ofsuch a maneuver are carried on to the surgical instrument itself andthus to the area of surgical application of the instrument. In otherwords, there is a greater tendency on the part of pivotal lever controlspreviously known in the prior art to bring about a jerking movement onthe grasped surgical instrument and after long periods of use bringabout muscle fatigue having a detrimental effect on the manual dexterityof the surgeon. Such jerking or jarring movements in controllingsurgical instruments of this type are eliminated by the type of levercontrol comprising this application since all movement of the levercontrol 86 is longitudinal relative to the surgical instrument 1.

Thus, the important features of the present invention reside in theprecise finger tip control of the valve means 67 to produce the desiredselective operating speed of the rotor 31 and the application of anoutput spindle 14 rotatably driven by the rotor 31 through the spindle46, being angularly disposed relative to the latter permitting 6 aclarity of vision for the surgeon in the application of the surgicalinstrument 1 to the area of surgery.

FIG. 3 is a modification of the angularly disposed front housing 13 ofFIG. 1 wherein the front housing 13 has the nose cap 25 which retainsthe spindle assemblage within the front housing 13. The output spindle14, as in the case of FIG. 1, is rotatably supported in the bearings 15and is provided with the collet insert 20 for engagement in the slot 21in the spindle 14. The collet insert 20 is maintained in the slot 21 bythe collet spring 22 to frictionally engage the shaft of a cutting toolor burr inserted into the spindle collet 23 of the output spindle 14.

Unlike the sleeve 17 of FIG. 1, the structure of FIG. 3 is provided withtwo separate sleeves 96 and 97 which are spaced apart as shown at 98 andeach having a shoulder 100 at their opposite opposed ends to not onlyretain the coil spring 101 but also to retain the bearings 15 in asecured relationship as was the function of the bearing retainer 18 ofFIG. 1.

The rotor coupling assemblage of the structure of FIG. 3 comprises theknee discs 102 and 103 which have angularly disposed frictional engagingsurfaces 104 to properly transfer the rotary power of the spindle 46through its shaft 52 secured to the knee disc 103 to the angularlydisposed output spindle 14 through the knee disc 102. Continuousengagement of the frictional surfaces 104 is maintained by theapplication of the stored energy in the coil spring 101 against theshoulder 100 of the sleeve 96 and, thus, against the bearing 15 togetherwith the knee disc 102. The retaining ring 105 shoulders the supportbearing 47 against the shoulder 106.

It should be readily noted that the application of the friction discassemblage of FIG. 3 performs the function of a clutch through thetransmission of power to the output spindle 14. Thus, if the burrinserted in the collet 23 becomes overloaded, the friction discassemblage will permit slippage between the knee discs 102 and 103 andprotect the rotor 31 of the surgical instrument 1.

I claim:

1. In a pneumatically driven surgical instrument, an elongated housinghaving a pneumatically driven rotor mounted to turn within said housing,a front housing extending from said elongated housing rotatablysupporting an output spindle in the form of a collet for receiving acutting tool, means for connecting said rotor in driving relationshipwith said spindle, valve means in said housing to pneumatically supplysaid rotor, said surgical instrument characterized by valve actuatormeans comprising a slidable lever control adjacent of said elongatedhousing with its rearward end connected to a valve actuator slidablybiased in a recess in said elongated housing, a valve stem in said valvemeans with its end extending into said valve actuator, a buttressslidably guidable on the forward end of said elongated housing andsecured to the forward end of said lever control, said valve meanscomprising a valve body on said elongated housing having a valve chamberand having an inlet on the valve chamber side and an outlet in a valvechamber end wall, a ball valve seated in said valve chamber for pivotalrotation between a pair of aligned elastomer O-rings and having acupshaped recess therein to direct a desired amount of pneu matic supplyfrom said inlet to said outlet upon operation of said valve actuatormeans.

2. In the pneumatically driven surgical instrument of claim 1, saidvalve actuator block provided with actuator lock means to hold andmaintain said valve actuator means in a selected position, said buttresshaving a finger pad receiving area.

3. In the pneumatically driven surgical instrument of claim 1, saidfront housing characterized by being angu-' larly dispose-d relative tosaid elongated housing, said means for connecting said rotor in drivingrelationship with said output spindle comprising an angularly disposedpower transferring coupling assembly.

4. In the pneumatically driven surgical instrument of claim 3, saidpower transferring coupling assembly comprising a pair of angulardisposed rotatably supported knee gears, one secured to said outputspindle and the other secured to said rotor.

5. In the pneumatically driven surgical instrument of claim 3, saidpower transferring coupling assembly comprising a pair of angulardisposed, rotatably supported discs having friction engaging surfaces,one secured to said output spindle and the other secured to said rotor,at least one of said discs spring biased toward the other to maintaincontinuous frictional contact between said friction engaging surfaces.

6. In the pneumatic control for a pneumatically driven surgicalinstrument, an elongated housing for supporting a pneumatically drivenrotor mounted to turn within said housing, a valve body secured to saidhousing having a valve chamber to receive a spherical valve having acupshaped recess, a pneumatic supply inlet to said valve chamber and apneumatic supply outlet connected to a passageway to said rotor, saidspherical valve having a valve stem and rotatably supported in saidvalve chamber within a pair of aligned elastomer O-rings, a valveactuator means comprising a longitudinally disposed lever controladjacent to said housing and slidably guided therealong, a valveactuator secured to one end of said lever control and slidably biased ina recess in said valve body and having an opening to receive said valvestem, a buttress secured to the other end of said lever control andslidably guidable on said housing.

7. The pneumatic control for a pneumatically driven surgical instrumentof claim 6 characterized by an actuator lock means to hold and maintainsaid valve actuator means in a selected position, said buttress having afinger pad receiving area.

8. In the pneumatic control for a pneumatically driven surgicalinstrument, an elongated housing for supporting a pneumatically drivenrotor mounted to turn within said housing, a valve body secured to saidhousing having a valve chamber to receive a rotary valve having acupshaped recess, a pneumatic supply inlet to said valve chamber and apneumatic supply outlet from said valve chamber connected to apassageway to said rotor, said rotary valve having a valve stem androtatably supported in said valve chamber within a pair of alignedelastomer O-rings, a valve actuator means including a longitudinallydisposed lever control adjacent to said housing and slidably guidedtherealong and having anopening in the rearward portion thereof toreceive said valve stem.

References Cited UNITED STATES PATENTS 2,855,671 10/1958 Lundgren et al.2,923,060

EVERETT'E A. POWELL, JR., Primary Examiner.

US. Cl. X.R. 32-27

